When I pushed the button, the metal door slid open. Once I stepped inside the door, it slid closed and locked. A mechanical voice said that I had a maximum of, I think it was ten minutes, to use the facilities before the door opened automatically.
The entire inside was tiled and had a steel toilet and a steel sink in a recessed side panel. It indicated that once you left, the entire room was automatically cleaned.
Once I finished using the toilet, a light was flashing over the sink, and a voice directed me to wash my hands. I had to press another button to slide the metal door open and it immediately slid closed behind me once I exited.
I have to admit that I felt pretty secure that no one was going to interrupt me while I used this secure toilet room and it was sure clean and shiny inside.